Now the files in the "standard" directory show a normal split screen using 5 sprites on a line as split point.The code works in emulators and shows two sat's of 32 sprites (total 64) on the same screen.The last 5 sprites of the upper sat have to be sacrificed as placeholders for line split

The files in "active sprite counter" directory show a screen split using just one sprite as split pointThe code does not work properly on emulators and I have to test it (I hope tonight) on real HWThe last sprite of the upper sat is sacrificed as placeholders for line split so you can use 63 sprites freelyAfter the tests on real HW I'll tell if it works as expected.

I've just tested files in "standard" directory and those in "active sprite counter" directory on my TR and only the split screen that uses the 5th sprite flag works.

In order to reproduce hap's results on the behaviour of "sprite counter" of the status register more tests and investigations are needed.

Anyway, Dioniso, if you can, try the standard files. The split screen works great and I expect nothing strange on msx1 vdp's.

I have also tried both ROM in a MSX1 HB-75D. The "sprite counter" one doesn't work properly and everytime I reset de MSX I have a different result; showing 8 sprites at the top and none or 32 at the bottom. Could it be the way of writing to the VRAM?

I could reproduce the SCREEN 2- SCREEN 3 - SCREEN 2 screen splits I coded with syncho code using your technique of the 5th sprite flag but not with the "active sprite counter". Thanks for the code. If you want to do some tests on the HB-75D (Germany, PAL) just tell me. I also have some others MSX1 computers:

Thanks! Actually I'm starting to think that hap's ideas about the status register working as "active sprite counter" is just a mental trip :-)

I did some more tests on my TR without success: if the feature exists and turns out to be only present in TMS9918 (and equivalents) but not supported by V9938/58, it could be not worth of being emulated and used in actual SW.

I'll try to do a test rom where the position of the placeholder can be changed by keyboard.In this way it should be possible to pass from "standard" screen split with 5th sprite condition to "active sprite counter". I let you know asap.